I've worked diligently at stowing away our "coupon savings" for the past year and a half. I do pretty good at bargain shopping (he does not), so as incentive, if I save a couple bucks on a grocery order the difference goes into my vacation jar.
He's aware of the fund, but has no idea how much is in it. I'd like to surprise him with a trip to a deluxe resort so I figure it'll be a couple more months before there's enough there.
Bonus is now he'll see that coupon savings really do add up!